\documentclass{minimal}

\usepackage{newtxtext}
\usepackage[UTF8]{ctex}

\usepackage{lipsum}
\usepackage[most]{tcolorbox}
% user defined color
\usepackage{xcolor}
\definecolor{thinkcolor}{RGB}{227,196,144}
\definecolor{observecolor}{RGB}{153,201,227}
\definecolor{explorecolor}{RGB}{178,217,200}

\tcbset{
    common/.style={
		enhanced,
		arc=0mm,
		fonttitle=\large\bfseries,
		coltitle=black,
		attach boxed title to top left={xshift=0mm,
										yshift=-0.50mm},
		boxed title style={
			skin=enhancedfirst jigsaw,
			size=small,
			arc=5mm,
			bottom=0mm,
			left=8mm,
			right=18mm,
			top=1mm},
			boxrule=0pt,
			frame hidden},
    thinkstyle/.style={
		common,
		colbacktitle=thinkcolor,
		colframe=thinkcolor,
		colback=thinkcolor!40,
		borderline north={4pt}{0pt}{thinkcolor}},
	observestyle/.style={
		common,
		colbacktitle=observecolor,
		colframe=observecolor,
		colback=observecolor!40,
		borderline north={4pt}{0pt}{observecolor}}
}

\newtcolorbox{think}{thinkstyle,title=思考}
\newtcolorbox{observe}{observestyle,title=观察}
\newtcolorbox{custom}[2][gray]{
	common,
	title=#2,
	colbacktitle=#1,
	colframe=#1,
	colback=#1!40,
	borderline north={4pt}{0pt}{#1}}


\begin{document}

\begin{think}
	\lipsum[2].
\end{think}

\begin{observe}
	\lipsum[2].
\end{observe}

\begin{custom}{探索}
	\lipsum[2].
\end{custom}

\begin{custom}[explorecolor]{探索}
	\lipsum[2].
\end{custom}

\end{document}